


You're Mine

by Saiyurimai



Category: Undertale (Video Game)
Genre: Angst, Angst and Fluff and Smut, Enemies to Lovers, F/M, Kidnapping, Underfell AU, Violence, sorta happy ending?
Language: English
Status: In-Progress
Published: 2018-05-23
Updated: 2018-05-23
Packaged: 2019-05-10 11:12:01
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 4,228
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14735873
Author URL: https://archiveofourown.org/users/Saiyurimai/pseuds/Saiyurimai
Summary: Frisk has found herself in a strange new timeline with a strange new version of the monster that she loved once. But he's violent and scary...he's not her Sans anymore. But can she learn to love this version as she did the original?





	1. Chapter 1

**Author's Note:**

> This is actually one of the first fics I wrote for the fandom so I've actually had it finished and sitting on my computer for over a year now and I've been contemplating whether or not to post it for seriously months. Tags will be updated as I continue to edit and read through it again. Thank you so much for reading!

“Hey kid? Kid. Hey HUMAN!” Frisk was awoken suddenly by a whack of dirt to the face. With a groan she wiped the dirt from her face and opened her eyes to stare up at the now familiar face of Flowey the Flower. “Flowey? What happened to your petals?” The flower sighed and moved away so she could roll over, kneeling in the small mound of flowers. Frisk rubbed her back as she looked around at the Ruins idly. What am I doing here? Did I reset? I don’t remember.

 

Frisk frowned as the small flower looked up at her in curiosity. “You’re not supposed to be here. You’re too old for this timeline.” The flower squinted up at her, tilting his head to the side. “Well that happens when a human grows up. I can’t stay nine years old forever. Wait what timeline is this? It looks different somehow.” Flowey was about to say something when a set of footsteps echoed through the stone halls, his face falling in fear.

 

“Hide! Whatever you do don’t come out until I say it’s safe! Now!” He whispered harshly to Frisk who was about to object but something in his terrified eyes told her she needed to listen to him. She hurried to hide behind one of the fallen pillars that scattered the area, daring a peek once she was sure she was far enough into the shadows to risk it. She was shocked as Toriel, her mom stepped out from the entryway, a menacing glare on her face as she stepped into the light, black cloak billowing around her ominously. She had a scar on her snout that made her look like she was always snarling and her normally pink eyes were a deep shade of red.

 

This was not the kind goat mom that had taken her into her heart and home. Frisk shrank back as Toriel came to stare up at the hole in the roof of the Ruins where Frisk had fallen through. The look on her face as she growled. “Where is the human you pathetic piece of trash?” Toriel growled, glaring down her snout at Flowey who was shaking in fear, wilting in her presence which wasn’t typical of the aggressive flower. “No human here. Just a rock that fell from somewhere up there.” Flowey’s voice was small but brave which made Frisk feel pity for the small thing.

               

“A rock? And you expect me to believe that crap?” Toriel’s paw glowed with the flame magic as she knelt down next to the shaking flower, his eyes focused entirely on the flames that glowed there dangerously close to his fragile yellow petals. “It was just a rock I swear! Sometimes rocks fall from up there! It happens! Please just don’t hurt me again.” The menacing Toriel gave a satisfied snicker at the terror in the flower’s face. A small tendril of flame catching a leaf, making Flowey wince in pain before she blew it out.

 

“Fine. If I catch you lying my flower I will rip off your petals one by one before setting your roots on fire.” Toriel kicked dirt and grass at the flower who took it with a shiver as the former queen glided off into the darkness. Frisk was about to move but the flower shook his head, holding up his singed leaf to signal her to stop. Several tense silent minutes passed by until Flowey waved her out from her hiding place. “Are you alright?” Frisk knelt down and reached out to look at the leaf but Flowey just waved her off with a sigh. “I’m used to it. Don’t worry about me though. You’re the one who’s in big trouble here.” Frisk frowned again, picking a cobweb out of her hair idly as she looked down at the flower.

 

“What are you talking about? What’s wrong with mom? I’ve never seen her this way before.” Frisk looked in the direction that Toriel had left, a little piece of her heart going with her. The flower sighed and followed her gaze. “This timeline is all kinds of messed up. Everyone who wasn’t violent and cruel before are now the exact opposite and everyone who was evil isn’t evil anymore. It’s ten times as dangerous as before and you are not supposed to be the one who comes through this timeline.” Frisk looked back down at him, brushing aside some dirt from his face much to the flower’s embarrassment.

 

“I don’t even know how I ended up here in the first place to be honest. One minute I was hanging out with the gang and the next I’m here, feeling as though I just actually fell down the hole again. I haven’t been down in the Underground in years.” Frisk looked back up towards the only source of natural light in the entire chamber, remembering the first time she’d fallen through as a kid. “That’s weird. I don’t know what to tell you then. Either way it really is kill or be killed down here now. Toriel’s only let me live this long because she can’t actually kill me.” Frisk looked around and noticed an old clay flower pot covered in dirt and cobwebs, walking over she bent down and dusted it off.

               

“I’m sorry. You shouldn’t have to go through all of this after everything you’ve already been through Asriel.” The flower winced as if he’d been stung at the sound of his real name while Frisk came back over to him, kneeling at his side and putting some soil into the bottom of the planter. “Please don’t call me that. I don’t really like it.” Frisk gave an apologetic smile and reached for him, the flower backing away with concern on his face. “What are you doing?” He asked and she put her hands back in her lap. “Well I don’t think I can handle knowing that mom is torturing you here and you know this place better than I do so I thought you might like to come with me?”

 

The flower hesitated, a soft smile on his face as he nodded slowly. Frisk reached out and furrowed her fingers into the soil, careful to avoid his delicate roots as she lifted him out, gently placing him into the pot just like her dad had taught her to do when transplanting plants. She grabbed another couple handfuls of rich soil and gently packed it around the base of his stem, making sure it was still loose enough he could breathe. “How’s that?” She asked as Flowey settled into his new home. “It’s a little small but I’d rather be here than getting stomped on by Toriel.” The flower smiled up at Frisk who returned the look, picking him up and walking towards the only exit which was the same way that Toriel had gone. “So what are the smaller monsters like around here? Are they scared or violent like the rest?”

 

Flowey looked around through the darkness, his eyesight better than hers was. “I’d suggest trying to avoid them as much as possible. They’re a lot stronger than you’re probably used to and probably won’t take kindly to you trying to get close to them.” Frisk walked through the area, sneaking through the area quietly, careful not to attract any attention to her or Flowey.

 

“How’re we going to get through Toriel’s house anyways? Or past that ghost?” Flowey asked once they were safely out of range of the monsters that were growling, pacing back and forth in agitation. “I’m not sure. What’s Napstablook like here anyways?” Frisk asked as they snuck around another intimidating looking Whismur quietly.

 

“He’s actually kind of cheery but in a creepy way. Like he just enjoys scaring the crap out of everyone and not in the harmless jumping out and screaming boo! It’s kind of hard to explain to be honest.” They came up to a bed of dead leaves where Frisk had always encountered the mild mannered and shy ghost but now it was empty. A cold breeze chilled her to the bone as she took a tentative step forwards, eyes peeled for anything out of the ordinary, she didn’t have anything to protect herself, just Flowey who was shaking nervously in his flower pot.

 

“Duck!” Flowey hissed and Frisk immediately knelt into the dried leaves, a little damp from who knew what sort of liquid. A second later a whooshing sound rush right by her head, feeling several strands of her hair fall loosely across her face. An evil cackle rang out hollowly through the small hallway and Flowey gave a whimper. “You’re fast for a human!” Frisk recognized the hollow sounding voice and felt a pang of sadness, hearing another sharp object rush towards her and rolling out of the way.

 

“If you stand still this could end a whole lot quicker for you!” Frisk hissed in pain as another object grazed her shoulder, tearing through her shirt and cutting her skin. “Blooky! Don’t you remember me? We used to be friends!” Frisk called out to the darkness as she tucked Flowey under her arm, pressing her body tight against the wall as several thin blades shot out from the darkness. “Hahahaha! Me be friends with a human?! Not a chance in your short miserable life!”

 

Frisk put Flowey down and raised her arms, looking around for any sign of the ghost in the surrounding darkness. “What about Dapperblook? The snail farm you and your family raise? Your mixtapes!” She cried out as something cut through the skin on her cheek, leaving a thin crimson streak of blood on her pale skin. Frisk didn’t move as a shape materialized in front of her several feet away, a curious look on his face as he stared at the human.

 

“Who told you about my mixtapes?” He asked and when she didn’t answer right away Frisk had to dodge another attack, her breathing heavy. “You did! You showed them to me once! We used to lay on the ground in your house and listen to them until it was like we had gone into another dimension! It was great! You made me one for my birthday a few years back and I love it! I listen to it every day!” Frisk used the back of her sleeve to wipe the blood from her face as Napstablook came a little closer, eyeing her carefully, unsure of her. “How come you don’t fight back?”

              

  Frisk lowered her hands to her sides and gave a soft smile. “Because you’re my friend. I don’t hurt my friends.” Tense silence filled the hall as Flowey stared nervously between the two who were focused on each other. “You really like my mix tapes?” The ghost finally said with a slight smile on his face and Frisk nodded vigorously and smiled a little bigger. “Yeah they’re really great. I’d love to listen to more of them if you’d let me.” The ghost thought for a moment, finally noticing Flowey and laughing softly, starting to look like his normal self.

 

“Huh. Maybe. But I don’t live around here so you’re out of luck right now. Hit me up in Waterfall if you manage to get past the crazy goat lady.” And with that the ghost just disappeared, Frisk heaving a sigh of relief as she picked Flowey back up. “I haven’t seen him just up and leave like that in all the years I’ve been here. That was crazy. Are you alright?” Flowey asked, pointing to her cuts and she shrugged them off. “They only sting a little but they aren’t that deep. I’ll live. I was actually worried for a bit.” She smiled and gave a nervous laugh as they continued on through the rest of the ruins in relative silence as they neared Toriel’s darkened house.

 

“Maybe she’s not home?” Frisk whispered as she crept up the stairs quietly. Cracking open the door a bit they could see the light from the fireplace in the living room glowing ominously. Frisk checked for any movement before sneaking inside, gently closing the door behind her and crossing the hall towards the stairs that led to the basement.

 

They were able to get to the bottom of the stairs without any problems, creeping along the dimly lit hallway to where the door was supposed to be to get to Snowdin. “That was too easy. I don’t trust this.” Flowey whispered into her ear as she rounded a corner, neither of them noticing the figure leaning against the door glaring at them until she spoke.

 

“I thought I smelled a human fall through earlier. I’m very disappointed in you Flowey. I thought we were friends.”


	2. Chapter 2

Frisk stopped in her tracks as the lanterns by the exit lit up to reveal Toriel snarling at her angrily. “Now human don’t make me get my cloak dirty. Human blood is just so hard to get out of my clothes. Put the flower down and stand still. This is going to hurt.” Frisk’s eyes teared up as she stood facing off against her mother even though they weren’t the same person they still looked similar.

 

“I don’t want to hurt you mom. I know that deep down you don’t want to hurt me either or Flowey. Just let us pass please.” Frisk cleared her throat, wincing as a snarling laugh came from Toriel who had flames in her palms. Frisk spun out of the way as a fireball was lobbed at them, barely missing the other three that followed quickly.

 

“Mom please! Please don’t do this! I know you’re better than this!” Frisk cried out as several more fireballs were thrown at them, Frisk doing her best to try and avoid them and keep Flowey from getting hit too. “Who the hell are you calling mom? I don’t have any children! Now just stay still!” Toriel growled angrily as Frisk dodged her attacks with some difficulty, Flowey noticing that she was moving closer with each attack. “Mom! Mom please just stop this! I love you!” Frisk cried as a fireball singed the ends of her brown hair.

               

Toriel growled and tried to throw another attack but Frisk put Flowey down and launched at the confused goat, Frisk’s arms wrapping around Toriel’s neck in an embrace. “What the hell?! Get off of me! What is your problem?” Toriel tried pulling Frisk off but the girl held on for dear life. When pulling her off didn’t work Toriel slung herself around, crashing into walls in an attempt to throw Frisk off or at least loosen her grip.

 

“Damn child! Get your hands off of me!” Toriel panted as she tried clawing at Frisk’s arms unsuccessfully. “No! I refuse! I’m not going to hurt my mom! I love you Toriel and deep down you love me too! I love your cinnamon and butterscotch pies and learning about insects and history! I love you mommy!” She cried out and Toriel stopped fighting, her red eyes softening slightly as she breathed heavily. “I love you. I love you mom. Please. I know you don’t know me but please know that I know you and I love you so much and love everything you’ve ever done for me.” Frisk cried, tears streaming down her face as she held onto Toriel tightly.

 

“I don’t deserve your love for all the crimes I’ve done to other humans.” Toriel whispered and Frisk shook her head. “I don’t care about that. You did what you had to do. I understand. You are still my mother and nothing can change that fact no matter what you’ve done in the past.” Frisk sobbed into Toriel’s fur, Flowey watching in curiosity as Toriel’s arms lifted shakily from her sides to embrace Frisk hesitantly, then more tightly as tears came from her eyes. “I forgive you mom.” Frisk whispered as Toriel cried silently. Finally, Frisk pulled away and held Toriel’s hands in hers.

 

“I have to go through the door and try and fix this. This isn’t the way the timeline is supposed to be. Everything is so different. It’s so wrong.” Toriel shook her head as she wiped away the tears from her fur with the back of her hand. “You can’t go out there. They’ll kill you on the spot! You can stay here and…” Toriel trailed off as Frisk shook her head with a sad smile. “I can’t stay mom. I’m the only one who can fix this, this mess of a timeline. Besides I know how to handle myself for the most part.” Toriel sighed heavily glancing at the door behind her before standing up and telling Frisk to stay for a moment as she ran back up to her house.

 

Frisk picked up Flowey and checked to see if he’d gotten hurt. Toriel came back with a small messenger bag that would sling over Frisk’s shoulders. “Here. You can’t defend yourself properly holding the flower. Take this too. Please.” Toriel handed Frisk a knife that was attached to a holster that hooked onto Frisk’s pants. “Thank you mom. I hope I won’t need to use it.” Frisk put Flowey securely into the bag so that he could see out over her shoulder as she put him on her back and adjusting the strap across her chest.

 

“I wish you didn’t have to go out there. There are really awful people out there and they are really strong. Cruel even.” Toriel warned as she walked them to the door that would lead them out of the Ruins. “I’m sorry. I’ll be careful I promise.” Frisk stood on her tiptoes and kissed Toriel on the cheek which made the monster blink in surprise a soft smile on her face as she reached for the door handle, unlocking it with a key attached to her wrist.

               

Frisk gave a final look as she and Flowey exited the ruins, snow blowing around them as the doors closed behind them. “How is it you’re able to make people just let you go?” Flowey asked as Frisk walked over to a bush, waving at the camera hidden within with a grin. “I just feel that there’s always good in people no matter how evil they seem. Why do you think I tried to save you?” Frisk stood and stared down the creepy snowy path that would lead them towards the town.

 

“Everyone has some good in them. I don’t think anyone is totally evil or unable to be saved. It does help knowing them when they were good.” Frisk smiled as she started walking slowly down the path when she suddenly started thinking about a certain skeleton. A skeleton that she realized would not be the one she was used to being around. Her steps slowed down, Flowey peeking over her shoulder as she came to the stick in the middle of the path.

 

“You ok?” He asked and Frisk took a deep breath. “I think I might be a little scared at what might come next.” Frisk spoke softly and stepped over the branch, sensing the figure behind her even before the snap of the branch reached her ears. “In my timeline we were…a little more than friends and I guess I’m not sure what to expect.” She slowed down, hearing the footsteps behind her slowing down as well. “It isn’t good. If you thought Toriel was bad he and his brother are worse.” Flowey brushed away a stray tear that had fallen from her eyes as she heaved a heavy sigh, resolving herself as she reached the bridge with the ineffective barrier which was decorated ominously with threatening messages.

 

Frisk heard the footsteps stop behind her, Flowey had retreated into the bag, shaking in his pot silently. A chilled breeze drifted loose snow all around her as she braced herself for what she would see behind her. “You gonna face me or not human?” Sans’s deep voice practically growled at her, Frisk licking her lips nervously as she slowly turned around, her eyes downcast, taking in the battered shoes that had dark red stains on them.

 

“You picked a bad day to show up here. Don’t know how you managed to get through the lady behind the door but you’re not getting pass me.” Frisk lifted her head as she felt her heart drop in despair as she stared at the skeleton, a thick black jacket with grey fur lining the hood and cuffs, red turtleneck and black and gold pants, a spiked collar and a gold tooth glinting in the low lighting. He was smirking at her, the eye that was normally blue in her timeline was now a blood red to match his shirt and shoes.

 

“Temmie got your tongue kid?” Frisk could sense the rage coming off of Sans and it scared her. She had never been scared of him before. “Don’t you remember me even a little?” She asked as Flowey peaked out of the top of the bag cautiously. “We used to be close friends. You used to put a whoopee cushion in her hand and when I shook it it would make you laugh. Do you remember the night in the echo flowers?” Frisk spoke softly as she took a small step forward, the skeleton narrowing his gaze dangerously at her approach. “Who the hell do you think I am? I’m not your buddy kid.” The red eye glowed dangerously as she took another step. “You should probably run now Frisk. He doesn’t remember you at all.” Flowey warned, Frisk stopping in her tracks.

               

“Oh for fuck’s sake you ain’t gonna cry now are you? I hate it when they cry.” Sans bent his knees as he prepared to lunge for Frisk who shook her head, tears silently falling from her cheeks. “I’m sorry. I can’t do this.” She whispered as she turned heel and ran through the woods, Sans in hot pursuit as Flowey hung on to the edge of the bag. “I love it when they run! It’s even better when they scream!” Flowey warned Frisk of the bone attack as she took evasive action. “Not gonna make it easy on me huh?” Frisk glanced back over her shoulder in time to notice the Gaster blaster taking aim at her.

 

“Hold on Flowey.” Frisk flipped Flowey to her chest, arms wrapped around the bag protectively as she dove into a roll, the heat of the blaster intense as it passed over them. Frisk scrambled up to her feet, Sans catching her by the strap of the bag and throwing her into the snow roughly. Frisk gasped as the air rushed out of her lungs on impact, still holding Flowey protectively as Sans approached with a satisfied smirk. “My boss is gonna love this.” He mumbled as he grabbed the front of Frisk’s shirt, Flowey hiding in the bag with a whimper. Frisk hissed as his fingers scratched her through her shirt harshly.

 

“It’s been a while since I had a good time like this.” His fingers pressed into her chest above her soul, drawing blood through her shirt as Frisk cried out, unable to move. “Stop! Just stop! This isn’t you!” She cried as he dug deeper making it as slow and painful as he could. “Ha! How would you know? You don’t even know me at all!” Sans chuckled, looking into her brown eyes which were silently pleading for him to stop.

 

“I do Sans! I know you like puns and practical jokes! I know you love your friends and your brother! I know that you love me!” Sans hesitated a moment as he met resistance from her soul. “I know you’re ticklish on your ribs and that the first time we kissed you were so nervous that I could hear your bones shaking and you couldn’t put a whole sentence together. I know you loved me, that why you took me to the echo flowers. You had whispered it to them and sat me down in the middle of the field and asked me to marry you. I also know that I said yes before you even finished your proposal.” Frisk whispered softly as her determination grew with every word, pushing Sans’s hand away from her soul while he was distracted.

 

“That was real? I thought it was just some weird ass dream…” He whispered, the snow blowing around them as Frisk breathed heavily, a hand putting pressure on her chest over his hand which made him wince and pull away with a snarl. “That’s my timeline. The one I was in before this one. You should know it well. You always did know about the other timelines.” Frisk sat up so that she was inches away from Sans’s face, her fingers stained red with her blood as she reached out to touch him which in his confused state he allowed for a second before pulling away from her with another snarl of distaste.

 

“Shut the hell up human. I’ve got to take you to my boss. He’ll take care of you.” Sans grabbed her by the back of her neck and forced Frisk to her feet, Frisk stumbling a moment before gaining her footing. “Get moving.” He growled and shoved her harshly from behind, Frisk stumbling again as she walked ahead of the grimacing skeleton.


End file.
